## Heisenberg Indeterminacy Post Assessment #18

$\Delta p \Delta x\geq \frac{h}{4\pi }$

Julia Lindner 1I
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Joined: Fri Sep 28, 2018 12:17 am

### Heisenberg Indeterminacy Post Assessment #18

"The hydrogen atom has a radius of approximately 0.05 nm. Assume that we know the position of an electron to an accuracy of 1 % of the hydrogen radius, calculate the uncertainty in the speed of the electron using the Heisenberg uncertainty principle.
Comment on your value obtained."

What does it mean that you know the position to an accuracy of 1%? I assumed that meant you multiply .01 by 0.05 nm, which gives you the delta x. But I tried using that value to obtain the uncertainty in speed and I didn't get one of the listed answers. Anyone know what I'm doing wrong? Could it be just a calculation error?

Chem_Mod
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### Re: Heisenberg Indeterminacy Post Assessment #18

You are correct in assuming that the uncertainty will be 0.01 x 0.05 nm- be sure to work through the calculations carefully since I believe that you may have made a calculation error. Have you taken into account the mass of an electron?